SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'facf36c98a77ae4b8377ffebc94a06ac743fe461d5cfe2855f85b9fb25d6261b' 
  AND token = 'ydb+8KP2HdQmUNj63lHHkKwWudR3UF5WIOkwJCFzJmY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}